The present invention relates to workbenches having clean air work areas, and more particularly to improvements in the delivery and distribution of filtered air for such benches so that a workbench is provided wherein a zone of clean air is extended beyond the normal work surface of the workbench.
It is known to provide a workbench which has an air filtration system that delivers clean air over the work surface of the workbench. A circular work center of this character is disclosed in United States Letters Patent No. 3,537,381, issued Nov. 3, 1970 to Philip R. Austin. In this work center, the work area extends around the entire circumference of the work center and air is directed radially outwardly from the center thereof. It is also known to provide a workbench wherein a rectangular work area is provided and in which the air is directed linearly outwardly from the rear of the work area. An example of a construction of this type is shown in United States Letters Patent No. 3,336,855, issued to A. J. Messina, entitled "Ultra-clean Workbench." Work centers or workbenches of the type disclosed in the prior art are limited in the degree of efficient air filtration that can be realized at the work area. In the prior art devices the movement of the filtered air beyond the work area is quickly dissipated, and in some instances eddy currents and the like may result in the return of unfiltered air and impurities into the region immediately adjacent to or even into the work area. Thus, there is need for further improvements in this field for a workbench which is characterized by its ability to provide ultra-high efficient air filtration in the work area.